Conventionally, configuration information, a computer program, and the like (hereinafter, referred to as “configuration information and the like”) related to a storage system have been stored in a flash memory provided in a storage controller (hereinafter, referred to as a “controller”). However, with increasing capacity and higher performance of storage systems, a volume of configuration information and the like has increased and can no longer be stored in a flash memory. Therefore, storing configuration information and the like in an SSD (solid state drive) provided in a controller for storing cache data (referred to as a “cache SSD”) instead of in a flash memory is being evaluated (PTL 1, PTL 2).